The present invention relates generally to digital storage systems. More specifically, the present invention relates to a transport mechanism for transferring cartridges between tape libraries of a storage system and a method for transferring cartridges between tape libraries of a storage system.
Automated storage systems are used for storing and retrieving relatively large amounts of information in digital form. One type of storage system includes one or more individual tape libraries that are positioned adjacent to each other. With this type of system, each tape library can include a library housing, a plurality of cartridges retained in a plurality of storage bins within the library housing, a robotic cartridge handling mechanism and one or more cartridge readers. The robotic cartridge handling mechanism individually retrieves one of the cartridges from one of the storage bins and places the cartridge within one of the cartridge readers.
In certain instances, the information contained in one or more of the cartridges is in more demand than the information contained in other cartridges in the storage system. If these high demand cartridges are in the same tape library, the throughput of the storage system can be diminished because the cartridge handling mechanism and/or the cartridge reader is over burdened. In order to increase the throughput of the storage system, it is often necessary to distribute the high demand cartridges among the tape libraries. Further, if one or more of the cartridge readers of one tape library fail, it may also be necessary to transfer cartridges to another tape library.
Transfer mechanisms have been developed to transfer cartridges between tape libraries without interfering with the operation of the tape libraries. These transfer mechanisms typically include a frame and a receiver that receives the cartridge. Unfortunately, existing transport mechanisms are not completely satisfactory. In particular, existing transport mechanisms can take-up too much space within the tape library and/or require too much clearance to operate in the tape library. Further, existing transfer mechanisms can interfere with the operation of the cartridge handling mechanism. Moreover, some of the transport mechanisms require a relatively large opening through the tape library for clearance of the transport mechanism. The large opening can weaken the structure of the tape library.
In light of the above, it is an object of the present invention to provide an improved transport mechanism that transfers a cartridge from one tape library to another tape library in a storage system. Another object of the present invention is to provide a transport mechanism that does not interfere with the operation of the cartridge handling mechanism. Still another object of the present invention is to provide a transport mechanism that minimizes the opening required in the tape library for the transport mechanism. Yet another object of the present invention is to provide a storage system having improved durability, which is relatively easy and cost efficient to manufacture and utilize.
The present invention is directed to a transport mechanism for moving a cartridge between tape libraries that satisfies these needs. The transport mechanism includes a frame, a transporter and a mover. The frame extends between the tape libraries. The transporter selectively receives the cartridge. The mover moves the transporter along the frame between the tape libraries.
Uniquely, the mover also pivots a portion of transporter and the cartridge relative to the frame during movement between the tape libraries. More specifically, the mover pivots a portion of the transporter and the cartridge between an almost horizontal, load/unload position and a transport position. In the transport position, the cartridge is securely retained in the transporter and the transport mechanism is more resistant to shock and vibration excitation. This increases the stability of the transport mechanism and reduces the likelihood of damage to the cartridge.
Further, in the transport position, the transporter has a smaller horizontal profile. With the smaller horizontal profile, the transporter can pass through a relatively narrow opening in each tape library. The smaller opening is advantageous because the structure of each tape library is not compromised. Additionally, the smaller horizontal profile provides more space in each tape library for the cartridge handling mechanism and the other components of the tape library, such as drive belts and electrical cables. Moreover, the overall depth of each tape library near the transport mechanism can be smaller. This feature allows the tape libraries to fit through smaller doorways at the customer sights.
Preferably, the transport mechanism includes a latch that selectively secures the cartridge in the transporter during movement between the tape libraries. Basically, the latch inhibits the cartridge from falling out of the transporter during movement between the tape libraries. As provided herein, the latch is selectively moved between a locked position and an unlocked position.
Additionally, the present invention includes a method for transferring a cartridge between two tape libraries. The method includes the steps of positioning a transport mechanism between the tape libraries, positioning the cartridge in a transporter, and pivoting at least a portion of the transporter relative to the frame.